<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        html,body{
            width: 100%;
            height: 100%;
        }
        body{
            display: flex;
            justify-content: center;
            align-items: center;
        }
        .box{
            text-align: center;
            width: 400px;
            background: #fff;
            box-shadow: 0 0 10px #ccc;
            border-radius: 10px;
            padding: 20px;
        }
        p{
            margin: 10px 0;
        }
    </style>
</head>
<body>
    <div class="box">
        <h2>欢迎登录</h2>
        <div style="color: red;" th:text="${msg}"></div>
        <form th:action="@{/login}">
            <p>
                账号：<input type="text" name="username">
            </p>
            <p>
                密码：<input type="password" name="password"> <br>
            </p>
            <input type="submit" value="登录"> <br>
        </form>
    </div>
</body>
</html>